Build your own apartment composting unit, tips and tricks

How to build an apartment composter

Living the urban life in an apartment but would nonetheless love to make your own compost?
Even though it seems impossible at first glance, a technique called vermicomposting will let you to make real compost in an apartment.

Here is how to build your own apartment vermicomposter.

What is vermicompost?

Vermicomposting (from vermicompost) is a method that lets you produce your own compost indoors without any smell.

Vermicomposting concept

  • Appartment composting conceptCompost worms (called Eisenia foetidia) live in a container or box in which you throw organic matter.
  • These little critters will eat it up and the compost comes from their output – their poo.
  • Although some people succeed in making their compost without worms (with mushrooms, for instance), vermicomposting produces results much more quickly.
  • Moreover, you have nothing to do yourself, since your worms are working for you!

How to make an apartment composter

Vermicomposting kits in stores can run quite expensive. It is perfectly possible to make your own yourself instead.

For that you just need the following equipment

  • 5 identical containers, that stack on top of each other if possible,
  • wire mesh,
  • a blade or retractable knife,
  • manure or compost worms,
  • and a bit of green plant matter collected from a nearby field or park.

Simple plastic bins are great to start, or you can also ask fishmongers or supermarkets for Styrofoam boxes that are used to package food for instance.

Depending on the size of your household you may need to adjust the size. For example, a 2-person household needs bins that are 20 inches (50 cm) wide and 16 inches (40 cm) across. If 4 persons live together you’ll need roughly double the area, which translates to about 30 x 20 inches (70 by 60 cm).

In all cases, the bins should be at least 8 inches (20 cm) deep. And now for the handywork!

This is how your apartment composter should be set up

Bottom bin: Vermitea catcher

This is the ground floor (at the very bottom). It’s a bin that will recover liquid compost juice. Nothing to do here.

2nd bin: Vermicompost catcher

This bin has tiny holes that are too small for worms to pass through. It will catch the ready-to-use compost.

  • Spread small mesh-wire across larger holes along the bottom.
  • How small should the mesh be? About 1 mm (1/16th of an inch), the kind used to sift flour for example.
  • Use a plastic or aluminum mesh since metal would rust.

3rd bin: Worm and Scrap bin

The three active levels for an indoor vermicomposting unitThis bin has large 4-inch (10 cm) openings along the bottom, again covered with a wire mesh screen.

  • This time the mesh screen has holes that are twice as large, about 2 mm or 1/8th inch.
  • This is where the worms live and do their work.
  • Ready vermicompost falls from this bin to the one beneath it.

Optional 4th bin: Extension Worm and Scrap bin

For this bin, the entire bottom is removed so that it can serve to increase the capacity of your tower (except if the 3rd bin is already much deeper than the other ones).

Additionally, remember to close the top bin with a lid with a couple small holes drilled into it, because worms prefer working in the dark. If you found Styrofoam bins for this, you can also paint your apartment composter with dark paint to block out the light.

Launching and maintaining your worm colony

Once your apartment composter is ready:

  • Bedding made of scrap paper in an indoor vermicompost binadd a few leaves and twigs, as well as wet newspaper mixed in with soil: the “bedding”.
  • After that, add the worms: 1 lbs for a 2-person apartment composter, and around 3 lbs for a 4-person apartment composter.
  • At this point, don’t yet add your waste, since your worms must first settle in for a while.

Two weeks later, you can add your first worm food:

  • fruit peels
  • vegetable waste
  • teabags and coffee grounds
  • eggshells, etc.

Remember, don’t add:

  • any onions or garlic
  • fatty products like rancid butter
  • nor any meat and fish (not even bones and skin).

Images: CC BY 2.0: Lindsay Dee Bunny, CC BY-SA 2.0: kafka4prez, Oregon State University; dreamstime: HurricaneHank

Written by Gaspard Lorthiois | Loves helping out, especially when it comes to growing things. Worked in herbal medicine, runs a farm, and dabbles in tech. Master's degree and engineer.